Current mechanisms for detecting a vehicle driver's state based on a driver's control activity or activities, e.g., commands for acceleration, braking, and steering, suffer from certain shortcomings. For example, steering anomalies may warrant attention because certain patterns or activities may indicate a high driving demand condition or unsafe driver condition, such as fatigue or drowsiness. However, present mechanisms may not account for different driver states that may be reflected by driver steering activities detected at different frequencies.